1. Technical Field
The present invention relates to a seat to be used in a vehicle.
2. Related Art
In Japanese Patent Application National Publication No. 2010-500198, a side frame and a cross-member structuring a seatback frame are integrally formed of resin. In this seatback frame, a cross-sectional shape of the side frame forms a “U” shape whose open side is oriented to a seat width direction outer side.
When the cross-sectional shape of a side frame forms a “U” shape that opens to the seat width direction outer side, as described in Japanese Patent Application National Publication No. 2010-500198, an inflected end portion at the seat rear side thereof serves as an outer edge at the seat rear side of the side frame. Therefore, measures to ensure safety when an occupant sitting on a rear seat collides with the seat rear side outer edge (the inflected end portion) of the side frame are required, such as attaching a protective member such as a cover or the like to the seat rear side inflected end portion, or increasing the thickness of the inflected end portion and curving the outer face thereof into a circular arc shape.
Alternatively, if a side frame is formed with a “U” shape whose open side is oriented to the seat width direction inner side, there is no need to apply the measures mentioned above, because a corner portion of the inflected portion at the seat rear side serves as the seat rear side outer edge. However, there is a possibility of the inflected end portion at the seat forward side of this side frame impeding smooth inertial movement of an occupant sitting on the seat.